long mod = 1000000007;

void combinatorial(vector<vector<long>>& binomial) {
    binomial[1][0] = 1;
    binomial[1][1] = 1;
    for (int n = 2; n <= 300; n++) {
        binomial[n][0] = 1;
        for (int k = 1; k <= n; k++) binomial[n][k] = (binomial[n-1][k-1] + binomial[n-1][k]) % mod;
    }
}

int gridWalking(int n, int m, const vector<int>& x, const vector<int>& D, const vector<vector<long>>& binomial) {
    vector<vector<long>> oneDimension(n+1, vector<long>(m+1)), multiDimension(n+1, vector<long>(m+1)), endPoint = {{0}};
    for (int i = 1; i <= n; i++) {
        oneDimension[i][0] = 1;
        endPoint.emplace_back(vector<long>(D[i-1] + 2));
        endPoint.back()[x[i-1]] = 1;
        for (int K = 1; K <= m; K++) {
            long total = 0, temp1 = 0, temp2;
            for (int point = 1; point <= D[i-1]; point++) {
                temp2 = endPoint[i][point];
                endPoint[i][point] = (temp1 + endPoint[i][point + 1]) % mod;
                total = (total + endPoint[i][point]) % mod;
                temp1 = temp2;
            }
            oneDimension[i][K] = total;
        }
    }
    multiDimension[1] = oneDimension[1];
    for (int i = 2; i <= n; i++) {
        multiDimension[i][0] = 1;
        for (int K = 1; K <= m; K++) {
            long temp = 0;
            for (int l = 0; l <= K; l++) temp = (temp + multiDimension[i-1][l] * (oneDimension[i][K-l] * binomial[K][l] % mod)) % mod;
            multiDimension[i][K] = temp;
        }
    }
    return multiDimension[n][m];
}

int main()
{
    int t, n, m, k;
    vector<vector<long>> binomial(301, vector<long>(301));
    combinatorial(binomial);
    cin >> t;
    for (int i = 1; i <= t; i++) {
        vector<int> x, D;
        cin >> n >> m;
        for (int j = 1; j <= n; j++) {
            cin >> k;
            x.push_back(k);
        }
        for (int j = 1; j <= n; j++) {
            cin >> k;
            D.push_back(k);
        }
        cout << gridWalking(n, m, x, D, binomial) << '\n';
    }
}